So slim perhaps and supple (6)
I believe the answer is:
lissom
'supple' is the definition.
(I know that supple can be written as lissom)
'so slim perhaps' is the wordplay.
'perhaps' indicates an anagram.
'so'+'slim'='soslim'
'soslim' anagrammed gives 'LISSOM'.
'and' is the link.
(Other definitions for lissom that I've seen before include "Lithe and flexible" , "Supple or agile" , "'Lithe, supple (6)'" , "Limber" , "Gracefully slim and supple" .)